Copper alloy



Patented Dec. 20, 1938 UNITED sr COPPER. ALLOY No Drawing. Application April 11, 19st, Serial No. 72,09?

1 Claim.

This invention relates to copper alloys and processes for their production, and relates further to the hardening of metals and alloys.

In forming alloys from metals differing mate- 5 rially as to their boiling or vaporization points, precautions must generally be exercised to avoid excessive loss of the more volatile metals. In alloying metals 'such as copper and zinc, the

' latter of which vaporizes at a temperature below the melting point of the former, especial skill is required, and a particular problem is presented when the percentage of relatively volatile metal or metals is small.

It is an object of the invention to alloy copper with a small percentage of zinc or zinc and tin, by a process avoiding material vaporization loss.

Another object is to scalloy zinc or tin and zinc with copper as to assure a high degree of hardness for the alloy, while "avoiding brittleness.

In practicing the improved process, copper in any desired amount is first melted in a suitable crucible sufilcient borax being preferably added, when the metal has reached a red heat, to' promote fusion. when. the copper is reduced to molten form; there is added a quantity of arsenious oxide approximating three percent by weight of the copper, and there is then immediately added zinc, preferably in molten form, and in a quantity approximating five per cent by weight of the copper. During the addition .of the zinc, the molten metal is vigorously stirred, since otherwise the zinc will float upon the copper,

and homogeneity will not be attained. Ifphos-- phorus is to be an ingredient, it is now added in an amount approximating one per cent by weight of the copper, preferably in a red amorphous form and sealed within a suitable copper capsule or capsules. Vigorous stirring or other agitation of the molten mass is necessary to assure uniform absorption of the phosphorus. The effect of adding phosphorus, as described, is to increase the hardness of the resulting alloy.

The described process may be modified to impart increased ductility to the resulting alloy by omitting phosphorus, and adding sodium car- 5 bonate or potassium chloride after the arsenic compound has been introduced, in a quantity approximating two per cent by weight of the copper, or both of said salts may. be employed, each in a quantity approximating two per cent by weight of the copper. The best results 'are' obtainable by allowing an interval of a few minutes to elapse between the addition of; the arsenic compound and that of the other salt or salts.

The initially described process may be still 15 further modified by adding five parts (by weight) of'tin as soon as the copper is reduced to molten form, omitting the step of adding phosphorus. In this modification, the copper preferably constitutes parts (by weight) of the alloy. The 20 resulting alloy is somewhat less' hard than is produced by the first modification of the process. The electrical conductivity, heat conductivity, and melting points of any of the herein described alloys adapt them for, very satisfactory use as 25 welding electrodes.

What I claim is: w A copper alloy consisting substantially of the following elements in approximately the propor- PERSAK TOOKOUSIAN. 

